1. Field of the Invention
The present invention relates to document processing systems, to a system software interface that enables the same application software to be used across multiple document processing systems, and to improved jam recovery for document processing systems.
2. Background Art
A typical document processing system for feeding and transporting documents includes a feeder and a separator in the document feeding portion of the system, and a series of roller pairs or belts in the document transporting portion of the system. In the feeding portion of the system, the feeder acts with the separator to feed documents singly, in order, from a stack. In the transporting portion of the system, the roller pairs and/or belts convey the documents, one at a time, past other processing devices such as readers, printers, and sorters that perform operations on the documents. The feeder is typically a feed wheel, but may take other forms. The separator may be a wheel, but also may take other forms such as a belt. Further, the components in the transporting portion of the system may take a variety of forms. Various sensors located throughout the system are used to monitor documents as they pass through the system in a known manner.
Existing document processing systems include the Unisys Network Document Processor (NDP) 850, 1150, 1600, 1825, and 2000. Among other features, the NDP 850-2000 are capable of sorting documents into pockets and include an 8-pocket module, and additional pockets can be added in increments of 8, with a maximum of 40 for the NDP 850/1150 and 48 for the NDP 1600-2000.
The Unisys NDP document processors include the transport hardware and include system software that interfaces with the transport hardware to provide document tracking control. The system software includes a system software interface. The system software interface is a common application programming interface that enables the same application software to be used across multiple Unisys transports.
In existing document processors, throughput is measured by the number of items processed in a given time. When a document jam occurs, feeding must be stopped, and the operator manually handles the jammed document and each document that left the feeder after the jammed document had left the feeder. The current jam recovery procedure is very time consuming and degrades the throughput. An improvement in overall throughput can be achieved by reducing the time that the operator spends recovering from a jam or missort. In many instances, the operator is wasting time by validating that documents have been correctly pocketed, but current jam recovery procedure requires that the operator manually handle the jammed document and each document that left the feeder after the jammed document had left the feeder. Time can be saved if the operator is not required to search for documents that have been successfully processed and pocketed correctly.
In existing system software, a track control module monitors the transport hardware and when a document passes the reader and data is available, the track control module assigns or reads the tracking number of this item. An object is created within the system software that monitors the progress of this item from device to device until the document is pocketed and reports document complete to the application software through the common application programming interface.
The application software is expecting document completes to be returned in the order in which the objects were created. With existing system software, when a document jam occurs, the track control module will identify all documents from the first document involved in the missort or jam as being in an error state that requires the operator to manually recover. If a jam occurs in a pocket module it is likely that some documents following the current item may be pocketed correctly. The likelihood of this occurring is greater the further down the track the jam occurs. In the case of a missort, since documents that are in the track continue to run out, the likelihood of some of these documents reaching their correct pockets is very high. The existing system software will require that the operator validate all documents from the first document involved, including the validation of documents that had in fact been processed and pocketed correctly.
For the foregoing reasons, there is a need for a document processing system with improved jam recovery.